Ejection seat for aircraft



Oct. 24, 1950 J. MARTIN EJECTION SEAT FOR AIRCRAFT l2 Sheets$heet 1' Filed June 9, 1948 fwvenl'or JAMES MAR IN.

per

A l'lorney Oct. 24, 1950 J. MARTIN 2,527,020

EJECTION SEAT FOR AIRCRAFT Filed June 9, 1948 12 Sheets-Sheet 2 per/ Al'forney 12 Sheets-Sheet 3 171a 'enl'or JAMES MA TIN.

per

Ab'lorney Oct. 24, 1950 -rm EJECTION SEAT FOR AIRCRAFT Filed June 9, 1948 in 8 w w a w Oct. 24, 1950 J. MARTIN EJECTION SEAT FOR AIRCRAFT l2 Sheets-Sheet 4 Filed June 9, 1948 mm n 8 m ms M M Oct. 24, 1950 J. MARTIN EJECTION SEAT FOR AIRCRAFT 12 Sheecs-Sheet 5' Filed June 9, 1948 [nvenZ'or JAMES MA TIN.

jfler Oct. 24, 1950 J. MARTIN EJECTION SEAT FOR AIRCRAFT 12 Sheets-Sheet 6 Filed June 9, 1948 Oct. 24, 1950 J. MARTIN 2,527,020

EJECTION SEAT FOR AIRCRAFT 1 Filed June 9, 1948 12 Sheets-Sheet 7 N J I Inventor 4/ JAMES MARTIN.

MOW

Attorney Oct. 24, 1950 J. MARTIN EJECTION SEAT FOR AIRCRAFT 12 Sheets- Sheet 8 Filed June 9, 1948 Q fnl/eu-l'or' JAMES MARTINZ P Attorney Oct. 24, 1950 J. MARTIN 2,527,020

EJECTION SEAT FOR AIRCRAFT Filed June 9, 1948 12 Sheets-Sheet 9 Inventor JAMES MARTIN.

per

A l'l'ornqz Oct. 24, 1950 MARTlN 7 2,527,020

EJECTION SEAT FOR AIRCRAFT Filed June 9, 1948 12 Shets-Sheet l0 7 h Inventor JAMES MA TIN W W- J. MARTIN l2 Sheets-Sheet 12 EJECTION SEAT FOR AIRCRAFT Filed June 9, 1948 I Patented Oct. 24, 1950 UNITED STATES;

EJEo'r-IoN SEAT Fo RAntcaAF'r James Martin, Higher DenhairijEngland 1 Application June 9, 194s;:"s eria-1'No. 31.9131 1 In Great Britain July 10, 1947 with mechanism by which the seat maybe Apractical example of an ejection seat m;

launched from the aircraft by means; of an ejection unit actuated by pressure generated from one or more explosive cartridges; object of the invention is toprovide an improved C0111 struction and arrangement of the seat which enables the pan of the seat to be adjusted relatively to the frame to adapt it for use by. pilots or others of varying height or length of limb.

The invention is particularly applicable for use with the seat for aeroplanes described and illustrated in our patent application No. 638,762, filed January 3, 1946,. now U. S. Patent No. 2,467,763, issued April 19, 1949.1 The seat is-particularly suitable for use by-the pilot of a high speed aeroplane such as a jet propelled fighter type of aeroplane. The cabin of a hi'gh. speed fighter aeroplane is very restricted andthe hood is carefully streamlined and it is kept low so as to limit the extent to which it projects from the general contour of the aeroplane body.- The seat must be adjustable to enable the occupant to use the gun-sight correctly, -and to provide a proper line of vision for other; purposes. The present invention enables the desired adjustment to be made without increasing the height of-the hood and at the same time permits. theuse of a relatively long fixed stroke ejection'unit. r I

Another object of the invention isqto provide an improved construction and-arrangement of ejection unit or gun for ejecting thegseat and its occupant from an aeroplane; This-enables the seat to be locked in position' andto be,automatically released when the ejection mechanism I is actuated. It also enables 'theJ-seat' and the ejection unit to be easily and quickly released and detached from its mounting in they aeroplane for removal when required. The" invention ensures that the seat is positively and securely locked in position in the aeroplane but is instantly and automatically released when the ejection mechanism is actuated ormay be quickly released and removed by hand when required.

A further object of the invention is to provide improved constructional details to ensure effective and efiicient operation of the-ejection seat under all conditions and whenever required and at the same time to provide the maximum of protection for the occupant of theseat'whilst requiring a minimum of preparatory action on his part.

bodying the constructional features 7 and advantages of the present invention will .now'be described' in idetailcwith. reference to the ac wm anr a' ra r ssin W h. afront'perspective; pictorial vie pff Fl .is. l :1

j ;2 is a perspective showing the Ijetoi gun for expelling the seat from anaeroplaneand the seat adjustment and harness release mecha Figs. 9 and, 10 .-are side and front .elevation partly brokenawayand partly in sectiorrof 1 1 seat supporting and guide frame.

1 Fig. 11 is a; sectionalv plan viewofthe lower end of :the seatsupporting and guide frame.

Fig. 12 is a vertical section" through the combustion chamber and cartridge firing mechanism of t e ejectin m,

. Fig. 13 is,a vertical sectionfthrough the .loc y ingdevice for retaining the seat and the auto.-

,matic release mechanism for freeing Ithe'seat when the ejection lmis fired.

'Fig. 14 a plan viewpartly in section show;

nism and .also the .foot rests;

v V; .;Fig' ,.'j1'5 ig (nagrammauc view showing the seatafter it has been ejected frQm an aeroplane and having a drogueparachute which isbrought'out,

.andde veloped automatically. 'vation, through 7 the Fig -16 is a sectional el seat showingthe harness release mechanism. I V 1 -Figs.' 18 and 19 are longitudinal andftraris; verse sections of theharness release mechanism.

Figs. 20'and 21 arefront and side elevation of 1 the face. protecting screen.

Figs; 22Qand. 23 show a modified harness release mechanism and I 241s a sectional detail of a seat mountin abutrnent z- :I i. L

ing the seat supporting. and adjusting mecha barre lot the drogue parachute gun, partf of Referring more particularly to Figs. 1 to 5 of the drawings, the seat I is of sheet metal construction slidably mounted by its back 2 for adjustment in height on the seat frame 3 which is provided with rollers 4 which engage in channels in the fixed guide 5 see Figs. 4 and 5 to enable the seat and its frame to be ejected from the aeroplane in which it is mounted. Hand operated seat adjusting mechanism 6 is provided for raising or lowering the seat on its frame 3 to accommodate a short or tall occupant. Between the fixed guide 5 and the seat frame 3 is located the ejection gun (Figs. 2 and 3) for ejecting the seat from the aeroplane. This comprises a cylinder 8 and a ram 9 slidable on one another and which act between a mounting block I in the fixed guide and a cross beam II of the seat frame 3. The ejection gun is formed with a firing chamber for an explosive cartridge and is fitted with a removable breech block and firing mechanism for discharging the cartridge when it is desired to eject the seat from the aeroplane (more fully described hereafter). Mounted on the front of the seat frame 5 and above the back'2 of the seat I is a container 12 on the front of which is supported the shaped head-rest I3. Above the head-rest I3 is a handle I4 connected to a protective screen adapted tobe drawn down in front of the occupant of the seat and this handle and screen are connected by the flexible cable I5 to the cartridge firing mechanism so that the act of bringing the screen into position will actuate the firing mechanism to discharge a cartridge in the firing chamber to fire the ejection gun and eject the seat and its occupant from th aeroplane. The handle I4 is intended to be grasped by both hands of the occupant of the seat, so that the act of drawing the protective screen into position, automatically locates the occupants hands and arms in a compactly folded position against the body at the same time that the firing mechanism is actuated to eject the seat and occupant from the aeroplane. The pivoted hook I6 of relatively soft material, normally retains the handle I4 in the position shown in Fig. 1, but readily gives way to superior force when the occupant pullson the handle I4 with both hands.

In the container I2 is a compartment for a folded drogue parachute I! connected to the cross beam I of the seat frame 3 and on one of the side members of the seat frame 3 is mounted a drogue gun I8 with firing chamber for a cartridge and firing mechanism for its discharge after the seat has been ejected from the aeroplane. This is effected automatically by a static line I9 in a container anchored to the aeroplane, the static line being automatically released from the firing mechanism as soon as this has been actuated, thereby completely separating the seat from .the aeroplane. In a lower compartment in the container I2 is provided a releasable harness control mechanism having connections 2| for securing to the harness of the occupant of the seat and which are arranged to provide an effective anchorage for the harness whilst permitting a limited amount of freedom of movement when required. Footrests 22 are suspended beneath the front of the seat to receive the occupants feet and the side wings 23 of the seat correctly position his legs and prevent them from of aeroplane. The seat I is constructed of sheet metal so that the seat pan projects forwardly from the seat back 2 which has aehollow box form girder 30 at each side leaving a recess 3| in the seat back which fits over the seat frame 3 and the fixed guide 5. Figs. 9, 10 and 11 show the seat frame in detail and Figs. 6, '7 and 8 show the construction and arrangement of the fixed guide. Two light rigid frame members 32 having-flanged edges 33 are connected together at their upper ends by the cross beam II to which they are bolted so that the spigots 34 are firmly locked in the sockets 35 in the frame members 32. At their lower ends, the frame members 32 are each formed with a forwardly projecting lug 35 between which are bolted the flanged ends 3'! of a tubular distance piece 38. On the inner face of the frame members 32 are supported fixed bearing pins for two pairs of rollers 4 located at suitable intervals apart and near the lower end of the frame 3. These roller 4' engage in the two channels 40 at each side of the fixed guide-5 which is secured at its lower end to the bracket 4| adapted to be secured to the floor or other fixed part of the aeroplane structure. 7

The seat supporting and adjusting mechanism is shown inFigs. 1, 2; 4, 5 and in detail in Fig. 14; Within the hollow pan of the seat I is provided the transverse channel shaped stiffening member 42 beneath which are secured the lugs 43. Mounted to turn in bearingsvin the endsof the tubular distance piece 38 is a hollow shaft 44 on which is fixedly mounted the two lever arms 45 whose outer ends are pivotally engaged in the lugs 43 on the underside of the pan of the seat I. A diagonal strut 46 connects the inner end of one of the lever arms 45 with the outer end of the other lever arm 45 so as to impart stiffness to the structure and avoid side sway of the seat I. On one end of the hollow shaft 44 is secured the hand lever 41 by which the seat may-be raised and lowered. To permit this, short channel guides 48 are provided on the outer face of each frame member 32 and inwardly directed abutments 49 each supported on apivotal shaft 50 in the upper end of the seat back '2, engage in these guides 48 see Fig. '1. to provide a sliding and pivotal connection between the upper end of the seat back 2 and the frame members 32 of the frame 3. The seat I is supported by the lugs 43 pivotally connected to the forward ends of the lever arms 45 fixed on the hollow shaft 44'. Each of the lever arms 45 has a rearward extension 5| the end of which extends close to a quadrant 52 one of which is provided on. each of the frame members 32 and a'locking catch 53 is provided in each extension 5| to engage in any pair of holes 54 in the quadrants 52 to secure the seat I in any position to which it may be adjusted by the hand lever 41. The locking catches 53 are controlled by a press knob 55 on the end of the hand lever 47. This knob 55 is mounted in the end of a tubular push rod 55 connected also to the slidable wedge-shaped cam 51. This cam 51 has a pointed hook shaped end 58 which engages with a roller 59 on the end of a slidable cam plate 65 mounted to slide axially in the tubular shaft 44. The cam 51 is backed up by and slides against the anti-friction rollers 6|. The cam plate 60 slides against anti-friction rollers 62 and is pressed axially toward the cam 57 by the spring plunger 63 in the far end of the shaft 44. In the rearward extensions 5| of the lever arms 45 are slidably mounted the spring pressed tappets 63 t r ar nds of wh ch project and form the lockins gatchesf 53' which en age the jholsdn 'the quadrants '52. [The other ends 'of'tl' 'e' tap'pets 63 are forked to receive thecam'plate ana'a'r uer 64 on the end [of eacl 'iftappet'engages with' an inclined camface on the cam plate 6 0 and normally rests at the bottom of each *ca'm face 55 with the locking catches 53 projecting into engagement with a pair ofthe holes 54 in'the quadrants 52, Pressure' on the knob 55 will slide'the cam 57 against the roller 59 and force the cam plate 60 to move to the right against the' spring plunger 63. The rollers li' ffon the tappet's"63 wilfride up the cam faces '65 andthe locking cat'c'hes 53 will be withdrawn fr'omengagement with the quadrants 52. Movement of thehand levef'd'! up or down will raise or lower the'seat and when the knob 55 is released the locking catches 53 will again engage in the nearest'holes 54 in the quadrants 52 to lock the seat'in its new position.

In order to act as a partial counterbalance to the weight of the occupant of the seat and'to make it easier for him to adjust the seatwhilst seated therein, a pair of compression springs 86 in telescopic tubular housings are connected at each end to fixed pivot pins on the seat back 2 and on the frame memberstz, respectively. One of these counterbalance springs 66" is arranged. at each side of the seat, but only one can be'seen in Figs. 1 and 4.

' Footrests 22 arearranged beneath'thefiront of the seat I as seen in Figs. 1, 2,4, 5 and 14.1 These may be of hollow sheet metal'const'ructionior lightness and have rearwardly extending arms 10 having split bearings H by which they are mounted on the ends of the hollow shaft 44. The footrest structure T2 is suspended beneath the seat! by the suspension rods 13 pivotally con+ nected at their upper ends to the seat ii and engaging slidably in trunnionblocksM'Jpivdtally secured at each side of the'footrest structure" 12. Enlarged heads on the lower 'endsof the suspension rods 13 support the footrest structure when the seat is out of the aeroplane. Normally they rest on abutments on the aeroplane floor and the sliding connection 'permits freeadjustmentin the hei'gh't or the seat without interfering with the-correct position of the'footrests. Channel section-guides l5 4 and-'5) may be pro. 'Vided toass'is't"ind recting the occupants Ifeet onto; the footrests 22L' The guides 1-5 are readily ection-f 'gun' I is 'shownas aunit in Figs:

2"andj3 and so'me details in-"Figs. 12 an dus. The

outer: cylinder 8 is closed at its lower -end*=by the 'c'apj' 8i] having apart spherical; should'e 81 adapted to seat in 'thepartfspherical seat or the-mounting block my ectio -gun 1 is held'ag'a'inst displacement y the spr'ng pres'seol locking atch 83 'Whichengages" the: flanged end fi' of the cap as; An opening 85 intl'ie' fixed'guidei nables the locking catch;

831 to be withdrawn'to release the cylinder 81 r the 8366131011 gun 1 from the 'mount ing-b1dck rl0i Between flangesfafi on the'euts'ide' of the-cylinder 8-: is 'located "a' ringBl so that it may swivel on the" cylinder and hav'ing'spr ing fingers 88 adapted to engage flexibly against thfe' inner surface-of the fixed guide 5 so as to position the cylinder llwithin the guide 5, particularly when th "ram Q'haSTbQ3n removed. 7 7 "The tubular "ram 9 has; an openfpiston'- 90 and-is a slidable Working fit in the cylinder '8 and hasi'pa'ckihg' rings' to ensure afgais tight joint. 'Iri' the upper 'ierid of the ram 9"is sc uif'efd the fitting 91in which is'fo'ri'ried aL' C-hal'hbeiffO'r an" explosive'cartridgefl held in position were breech block 93 see 'particularlyFigs? 3"-an'd -12.

a The fitting 9 l hasapartsphericalflange 94 "which engages in anopening 55" the cross eam: Ii of the seat name '3 andagainst the'part-s'pherical seating 95 where it"ls' retainedby the spring Dressed loeking catchSi, Inthe breech blo'cli83 is fitted-a spring-loaded firing pin QB'slidably mounted'in the guide '99 and forked' at its upper end and fitted with'ja roller lflllfifIn' the forked end of the firing am ss "fits the removablewdg'e shaped sear I 0 i lia'vi 'i' g a hook H12 at its forward end with'which is connected theflexibl'e lead IS. The rear 'end of the Wedge shaped sear; is inclined "atfl B3 tdensureFthe ruuremdva of thesearfl'll l when the roller"ll]0 has passedthe peak of the I wedge shaped incline of the sear; A percussion jcap I M'isprOVidedin the cartridge;"positionedso separable from the footfests so as to be'lefube' V hind when 'the seat is ejected. when the occupants feet are plaed -on the footre'sts,*-*" sures that his legs will be folded compactly in front of his body in-a comfortable and protective position so that they will pass freely through the available opening in the aero'plane when the seat is ejected therefrom. It will thus be s'een that the occupant of the seat automatically assumes a compactly folded position adaptedfto protect his body and vital organs against thec'onditions and stresses which will be met when the seat is ejected from an aeroplane in flight. v

The seat I and its frame 3 are slidably mounted on the fixed guide 5, Figs. 4, 5, 6, 7 and 8; The fixed guide is a rigid rectangular column secured at its lower end by a bracket 4i anchored to a structural part of the aeroplane so that the guide. 5 is directed upwardly toward an opening'in the aeroplane cockpit. The guide mmed with channel guides at at each side in which engage the rollers 4 on the frame members 3'2 of the seat frame so that the seat frame 34 fits aroundthe is en fixed guide 5 as seen in Figs. 5 and' ll; In the a that it will be struck by the 'firing'pin 98 when r {the cartridge firing mechanisinis actuated' by a' pull-on the'flexible'cableil 5. Norm'ally the spring n'f' the' firing pin is only lightly compressed. When 7 thejcartridge firing "mechanism hafs 'toj be acmated, pull on the cable l5fwithdiaws the 'sear 'lfli 'and' the first effect isto cause'the roller 10]) leased and is propelled-byTits springso strikethe percussioncapfleli of the 'c'artifidge he ram 9; This will fire the ram SengageS the satmgss "m; the'cross beain n of tneseat frame a, the latterwith the 's'eat f a m a W llfie P f 5 el1 qa 9 th guide-Qand'tl' eJ'b ejotdifrdmfthe g The cylinder Boffth chamber "between them. In order to maintain or increase the efiective pressure within the expansionchamber, at least one chamber- I05 for an auxiliary cartridge I05 may be provided on the side of the cylinder 8. At least one opening I01 communicates between the interiorof the cylinder 8 and the chamber I05 so that as the ram uncovers the opening I01, the hot gases in the cylinder will ignite the explosive material in the cartridge I08 which will then discharge its gases into -t he expansion chamber between the cylinder 8 and the ram 9. The cartridge I06 may .have a perforated cover plate I08 with a thin layer of material I09 such as metal foil over each opening. Variation in the size of the opening thickness of the foil and the nature of the material, will-enable the character and rate of combustion of the explosive material to be controlled. A sliding panel IIO (Fig. 1) permits access to the chamber I05 for the removal or replacement of auxiliary cartridges I06.

It is essential to be able to eject the seat freely from the aeroplane directly an emergency arises to make this necessary but it is also necessary that the seat shall be positively secured in the aero-- plane at all other times. For this purpose a lockingdevice is provided to secure the ram 9 to the cylinder '8 which is locked to the mounting block I fixed in the guide and this is securely anchored to a structural part of the aeroplane. This locking device is adapted to be instantly and automatically released when the ejection gun I is operated. The piston end 90 of theram 9 has an. internal bevelled flange H I: and this engages in a channel in the upwardly directed rim II-2 of the cap 80 secured in the lower end of the cylinder 8. This rim is divided by a number of radial slits into a series of spring fingers I I3 which will readily contract or expand to enable the flange III on the piston end of the ram 9 to engage and disengage from the channel in the ring of spring fingers I I3. These spring fingers are normally locked in the engaged position shown in Fig. 13 by means of the protruding rim I I4 of the locking piston II5 which is slidably mounted in the cap 80 and has a spring I I6 which normally urges it upwardly and a knob I IT. The .ram 9 and cylinder 8 are thus securely locked together but the lock will be instantly released when. the gases from the exploded cartridge 92 press back the locking piston II5. This is entirely automatic and requires no action or forethought by the occupant of the seat. The knob I-II enables the lock to be released by hand without firing the cartridge, when it is required to disassemble the gun or for other purposes.

When the seat has been ejected from an aeroplane, a drogue parachute is automatically released and developed to steady the seat in the air and prevent the occupant being subjected to wild gyrations which might render him incapable of taking the further steps required to ensure a successful parachute descent. The drogue parachute I I is connected to the cross beam I I of the seat frame 3 by the strong nylon cables I20 connected to the eyes I2I fixed in the cross beam II and is stowed in the upper compartment of the container I2 beneath the neatly folded flaps I22. The drogue parachute I1 is withdrawn from the container I2 and is projected upwardly away from the slip-stream of the aeroplane by means of a drogue parachute gun I8 which is shown in Fig. 4 detachably mounted on the side of one of the seat frame members 32 by means of releasable clamps I23.

the seat.

The drogue gun l8 -is provided with a .chamber for a cartridge and is fired by cartridge firing mechanism I24 similar -tothe firing mechanism of the ejection gunI. The trigger I25 is operated automatically by a static .line I9 detachably connected to the trigger I25 so as to be instantly released from it directly the trigger has been pulled thus leaving the seat-I entirely separated from the aeroplane. The static line I9 runs through the tubular guide I26 on the sideof the seat frame 3.

The seat I is .shown after ejection from the aeroplane and with the drogue parachute I I developed, in Fig. 15 and Fig. 16, shows details of the drogue gun I8 in sectional elevation and to a larger scale. The body I30 of the drogue gun I8 contains the firing mechanism I24 which includes the spring loaded firing pin I21 adapted to be drawn back and released by the wedgeshaped sear I28 acting on the roller I29 supported in the forked -endrof. the firing pin I2'I. The trigger I25 is pivoted to brackets I3I on the body of the gun and is connected to the sear I 28 by the lever I32. An eye on the end of the static line I9 normally engages in the slotted end I33 of the trigger I25 and isretained against accidental displacement by the spring pressed guard I34. The guard I34 readily gives way to enable the eye on the static line I9 to be pulled out of the slot I33 when the trigger is turned down after having fired the gun. The barrel I35 of the drogue gun is screwed into the body I30 of the gun and thereby closes the breech end of the barrel I35 which receives an explosive cartridge I36. A spring ring I31 encircles the breech end of the barrel and a pin on the ring projects through a hole in the barrel and presses on the cartridge case thereinso as to hold it in place when the barrel I35 is removed from the body I30. A spring ring I33 is located in a channel in the upper end of the body I30 and has a pin I39 which projects through a hole in the body I30 to engage serrations on the gun barrel I35 to prevent it becoming accidentally unscrewed. The gun has a piston I40 which is an easy sliding fit in the gun barrel I 35 (but is not shown in Fig. 16). It is however seen in Figs. 1, 4 and 15,but toa much smaller scale. It is attached by the cable I4I to the upper end of the drogue parachute I! so that this will be drawn-out of its compartment in the container I2 when the gun is fired and will be impelled well away fromthe seat andthe aeroplane so that it will open and develop satisfactorily. y

In high speed aeroplanes the: occupants are usually secured in their seats by connections to their harness. The harness release mechanism is shown in Figs. 2,17, 18 and 19. The pick up ends 2! on the security cables I are intended for connection to the personal harness of the occupant of the seat in the usual way to secure the occupant against accidental displacement during rough weather or when the aeroplane is performing evolutions such as steep banks, rolls or loops. The security cables I50 are wound upon reels I5I on the tubular shaft I52 mounted in bearings 453 in a housing I54 located in the lower part of the container I2 of A stout torsion spring I55 tends to wind the cables I50 on the reels I5I, the ends of the cables being secured one to each reel at I55. A locking catch I5! is spring pressed into engage ment with ratchet teeth I58 on one of the .reels I5I. The locking catch .I5'I may b withdrawn points 2 I.

by the levers I59 and I60 connected by the flexible cable I6! to a hand control lever I62 mounted on one of the wings 23 of the seat I. When the locking catch I51 is withdrawn, the occupant may stretch or lean forward, drawing the cables I50 off the reels II thus providing a. limited amount of controlled freedom of movement to the occupant of the seat, whilst maintaining a positive connection by which the occupants harness is anchored to the seat. The hand control lever I62 enables this control to be relaxed to allow a considerable amount of freedom to the occupant of the seat, but when the locking catch I51 is relased, the cables I50 will be automatically rewound and the reels I5I will be locked when the occupant settles back in the seat.

The head and face protecting'screen I10is 9 shown in detail in Figs. 20 and 21.

The screen is normally stowed in the container I2 but is se-' cured by its forward edge I1I to the cross bar I12 of the handle I4 by which it may be drawn down over the head and face of the occupant of the seat as shown in dot and dash linesin Fig. 4. When fully extended it will take the shape shown in Fig. 21 in which the centre section I13 is domed to fit comfortably over the face of the seat occupant. The upper edge I14 is folded over to form a loop for securing within the container I 2. The cable I5 for operating-the cartridge firing mechanism of the ejection gun 1 is connected to a loop I15 in a cable I16 embedded in the screen I10 and which has its two ends I11 folded round the cross bar I12 of the handle I4 and extended laterally and secured within the folded end of the material of the screen. In Fig. 20 the screen is pressed substantially flat to permit it to be rolled or folded forstowing in the container I2. The material of the screen is preferably a relatively stifi close woven canvas which will give the desired protection to the m 7 l a v the seat from'the aeroplanef'Firing of the carface, eyes, nose and mouth of the occupant but which will not be pressed tightly in place so as to prevent him breathing freely. Itmust however give full protection against inflation of the lungs by the great air press'urewhich will-be met by the occupant of the seat when it is ejected with an occupant, from an aeroplane moving "at high speed.

In an example of how the ejection seat'operates when fitted to a high speed fighter aeroplane, the

seat is secured in place in the cockpit'of the aero- 5 plane by securing the bracket '4 to the fioor or other structural part of the aeroplane, with the fixed guide directed toward the cockpit opening. The pilot sits in the seat and raises or lowers the seat pan means of the hand lever 41 so as to bring his eyes to the normal sight line for normal flying and for using the gun sight. This does not affect the height of the cockpit hood or detract in any way from the effective stroke of the ejection gun for ejecting the seat fromv the aero- :1:

plane. The pilot is secured in place by hisharness which is connected to the pick up anchorage This does not interfere with adjustment of the seat by the hand lever 41 assisted by the balance springs 66. a of movement is allowed if the hand control lever I62 is actuated to operate the harness release mechanism. The pilot thus occupies a compact and comfortable seat which conforms with'all normal requirements.

If an emergency arises or if after mature consideration, the pilot decides that it is necessary for him to make a parachute escape from the aeroplane, he only needs to jettison th cockpit Considerable freedom vtive screen I10 over his head and face. These actions automatically fold the limbs in a com- .pact' an comfortable position for ejection from .thefaeroplane and enable ,the pilot to withstand the (rapid acceleration to which he will be sub -jected during this operation. The protective "screen I10 will shield him against the effects 01 air pressure and blast which he will meet as soon as he is ejected from the aeroplanecockpit, The

ble cable I5 so as to actuate the cartridge firing mechanism to fire the cartridge92 in theej'ection 15 gun 1. The ga'ses'of combustion will increase the pressure in the space between the cylinder8 and the rams and this pressure acting on thelooking piston IfI5 will press it back so as to unlockthe connection between the cylinder'B and the ram 9. The pressure will then force the ram 9 and'the cylinder 3 apart arid when the piston end of the rams uncovers the opening I01 to the auxiliary cartridge "chamber I05, the hot gases will explode the cartridge I06 malts gasesof combustion will be added to those from the cartridge 92 so as to maintain the desired propulsive effect on the ram 9. ThisQis in turn applied to the transverse beam II of the seat frame 3 and the seat I and frame 3' will be propelledalong the fixed guide 5 and will be ejected with the'pilot from the aeroplane and well away from the tail plane, fin.and other parts of the'aeroplane.

.When the seat and the pilot has been ejected tridge I36 expels the piston'I40'from thedrogue gun I8 and draws out and developesthedrogue' parachute I1 as shown'in-Fig. 151 The drogue parachute I1 acts to'steady the seat and to prevent itgyrating wildly or turning overand'over 1 until it settles into a steady descent with its oc-' -cupant.* The occupant may now releasehim self from the seat and may pullthe ripcordof his parachute'in the normal way.

,, the seatmaybe readily removed from the aerofplane by releasing the locking catch 91'and lifting theseat out along the fixed guide 5. The ejection gun 1 may be readily detached as a unit 'by releasing the locking catch 83, and the locking piston II5 may be unlocked'by pulling on the knob H1 to enable the cylinder and ram to be;

separated. Fresh cartridges 92, I06 and I36 may be placed in their respective chambers. when required. All the parts are readily interchangeable-and replaceable.

An alternative arrangement of harness release I n'iechanism is shown in Figs. .22 and 23. Thesecurity cables I50 are wound upon two reels I5I each mounted in hearings in separate housings "I54 one of which is secured to each of the seat "frame members 32. Each cable I50 is'secured to its reel at I56 'and both reels have ratchet teeth 128 with which engages a locking catch I63. The two locking batches are connected by links |64-to levers I65 on a cross shaft I66 so that both locking catches I 63 will be released simultaneous- 1y by the cable i6I connected to one of them. A separate volute spring I61 is provide for each reel act of pulling on the handle I4 will pull the fiexi-- For purposes of inspection and maintenance i] and a detachable cover plate 58 is fitted to each housing 54. The arrangement is substantially similar to that shown in Figs. 17, 18 and 19 except that the separate housings #54 are each separately secured to the frame members 32 and the connecting tubular shaft I52, spring I55 and enclosing tube are omitted. Each cable 150 passes through a fairlead I58 on the side of the container I2.

A retractable pivotal abutment for mounting in the seat back 2 to engage the guides 43, is shown in Fig. 24. The pivot pin 50 is slidably mounted in the guides I86 in the upper part ofthe seat back 2 and its projecting abutment 49 normally engages in the guides 48 on the seat frame members 32, a COil Spring it! holds each abutment in engagement in its guides 48. A plunger'l82 is mounted in aguide 83 in the seat back} and a flattened wedge-shaped end l8 i projects into a slot I85 in the pivot pin 58 and engages a roller E85 mounted in the slot I85. By pressing on'the fianged end 58? of each plunger 32, the pivot pins 5% will be retracted thus withdrawing their abutments 39' from the guides 18 in the frame members 32.

back 2 from the seat frame and withdrawal of the pivot pins from the lugs 23 will enable the seat pan i and back 2 to be quickly released from its frame. ifhe shank of each plunger 82 serves as annanchorage for theupper end of the balance springs $6, which must be detached before the plunger can be actuated.

I. laim:

1 An ejection seat for aeroplanes comprising a seat having a seat pan and a seat back, a frame for the seat, guides on the seat frame, slidable and pivotalconnections between the seat back and the guides on the seat frame, side members to the seat frame,'a cross beam connecting their "upper ends forwardly ,projecting lugs at their lower ndsJ'a tubulai distance piece connecting these; lugs in spaced relationshipfa tubular shaft .rnounted in bearings in the tubular distance, piece, lever arms mounted on this shaft, connections fromthe endl of these lever arms to the underside -,of the seat pan, rearwardly directed extensions uto the 1 r arms and spring actuated locl ing catohe s ip these extensions, a hand leverbn the tubular shaft for raising and lowering the, seat inits guides on the seat frame, hand actuated .Ineans for releasing the locking catches, perforated quadrants on the seat framewith which the locking catches normally engage, an upwardly directed guide located between the side members of the;s eat frame, rollers on the seat framechan nels in the guide with whichthe rollers engage, means for securing the guide to a structural part ofthe aeroplane, an ejection gun releasably .be-

tweenabutments on the fixed guide and the cross Y hearn-ofithe seat frame and cartridge firing mechanism for discharging at least one cartridge in the ejection gun.

2. An ejection seat for aeroplanes, according This releases the seat -T to claim 1 having a protective screen adapted to bedrawn in front of the face and head of the occupant of the seat, a handle to the facescreen for this purpose and a connection from the handle to the cartridge firing mechanism of the ejection gun, footrests having rearwardly directed 12 claim 1 having a container mounted jon the front of the seat frame above the seat back aheadrest on the front of the container, at drogue parachute folded and stowed within the container, strong flexible connections from thedrogue parachuteto the cross beam of theseatframe, a 'drog'ue gun mounted on a member of the seatframe', a piston in the barrel of tiled-rogue gun, a cartridge-chamber and firing mechanism in the-body of thegun, automatic means for discharging the cartridge in the drogue gun after the'ejfictior-r-seat is clear of the aeroplane: andafiexible connection from the piston to the drogue parachute. I

4. An eject-ion seat foraeroplanes aecording to claim 1' having a container mounted onthe front, of the: seat; frame: above the seat back; a headrestpn' the flOl'ltjOf the container, a drogue parachute folded and" stowed within the-container, strong flexible connections from the drogue para-chute to the cross beam of the seat frame, a clrogue guninountedcn asnember of the seat" frame, a piston in the'harrel of the drogue gun, a cartridge'cham-ber between the barrel and body ofthe gun, a spring loaded'firing pin axially displaceable in the body of the gun, abutment on the firing pin, a transversely withdrawable wedge-shaped sear engaging the abutment, a" trigger device for withdrawing the wedge shaped sear; a sufficient length of static line stowed in a container and anchored at one end to the aeroplane, an automatically releasable connection at the other end of the static line connecting it to the trigger device so that it will be automatically released when the firing mechanism has, been actuated" to discharge the cartridge in the gun. r

5. An ejection s'eatfor aeroplanes according to claim 1 having a Container. mounted on thefront of the seat frame above the seat back, a headrest on the front. of the container, af drQguej'parachute folded and stowed Withidthe container, strong flexible connections from the drogueparachute to the cross-beam; of the seat frame, a drogue guflmountedj on a me. her of-the seat frame, a}, p ston ififlthe barrel of, the drogue gun, a ffi il me h nism n the body of'tlignnjautoniatic 'm e'anslioir dis; chargin the. cartridge in the droguefgun after the ejection seat is clear of the aeroplane and a flexible connection from the piston to the drogue parachute, a releasable harness connection for securing the. occupant in the seat comprising flexible cables with pick up, connectors for securing. to the occupants harness at least one housing mounted on the seat frame, a reel mounted in, bearings in each housing and on which the cables-are wound and anchored, spring means opposing unwinding of the cables, ratchet teeth on each of the reels, a spring loaded looking catch which engages each set of the ratchet teeth and hand controlled means for withdrawing eachlocking, catch, when desired.

6. An ejection seat according to claim 1 having an ejection gun comprising a cylinder disposed within the fixed guide, a mounting block secured in the lower end of the fixed guide, an end cap secured to the lower end of the cylinder, at part spherical collar on the end cap, a part spherical seating in the mounting block, a spring loaded locking catch securing the cylinder to the mounting block, .a hollowtubular ram slidable in the cylinder and projecting from its up end beyond the fixed guide, a cartridge chamber in a fitting secured in the upper end of the ram,

a part spherical flange on the fitting, a part,

spherical seating in a through opening in the cross beam of the frame of the seat and in which the ram engages a spring loaded locking catch which engages this flange, a removable breech block fitted in the breech of the cartridge chamber, a spring loaded firing pin mounted for axial movement in the breech block, an abutment on the firing pin, a transversely withdrawable wedge shaped sear engaging this abutment to first cock and then release the firing pin.

7. An ejection seat according to claim 1 having an ejection gun comprising .a, cylinder disposed within the fixed guide, a, mounting block secured in the lower end of the fixed guide, an end cap secured to the lower end of the cylinder, a part spherical collar on the end cap, a part spherical seating in the mounting block, a spring loaded locking catch securing the cylinder to the mounting block, a hollow tubular ram slidable in the cylinder and projecting from its upper end beyond the fixed guide, a cartridge chamber in a fitting secured in the upper end of the ram, a part spherical flange on the fitting, a part spherical seating in a through opening in the cross beam of the frame of the seat and in r 14 which the ram engages, a spring loaded locking catch which engages this flange, a removable breech block fitted in the breech of the cartridge chamber, a spring loaded firing pin mounted for axial movement in the breech bloclnan abut ment on the firing pin, a transverselywithdrawable wedge shaped sear engaging this abutmentfl to first cock and then release the firing pin, a

fiexible fabric face screen normally stowed in a compartment of the container on the seat frame, a handle outside the compartment and connected to the screen and a flexible cable connecting the handle and face screen with the wedge-shaped sear of the cartridge firing mechanism.

JAMES MARTIN.

7 REFERENCES CITED The following references are of record in the 

